Search results for "Algorithm"
showing 10 items of 4887 documents
Search forB0meson decays toπ0KS0KS0,ηKS0KS0, andη′KS0KS0
2009
We describe searches for B{sup 0} meson decays to the charmless final states {pi}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}, {eta}K{sub S}{sup 0}K{sub S}{sup 0}, and {eta}{prime}K{sub S}{sup 0}K{sub S}{sup 0}. The data sample corresponds to 467 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation and collected with the BABAR detector at the SLAC National Accelerator Laboratory. We find no significant signals and determine the 90% confidence level upper limits on the branching fractions, in units of 10{sup -7}, {Beta}(B{sup 0} {yields} {pi}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}) < 12, {Beta}(B{sup 0} {yields} {eta}K{sub S}{sup 0}K{sub S}{sup 0}) < 10, and {Beta}(B{sup 0} {yields} {…
Neutron to mirror-neutron oscillations in the presence of mirror magnetic fields
2009
We performed ultracold neutron (UCN) storage measurements to search for additional losses due to neutron (n) to mirror-neutron (n') oscillations as a function of an applied magnetic field B. In the presence of a mirror magnetic field B', UCN losses would be maximal for B = B'. We did not observe any indication for nn' oscillations and placed a lower limit on the oscillation time of tau_{nn'} > 12.0 s at 95% C.L. for any B' between 0 and 12.5 uT.
Updated Search for the Flavor-Changing Neutral-Current Decay D^0 \to {\mu} + {\mu}-
2010
We report on a search for the flavor-changing neutral-current decay D0 \to {\mu}+ {\mu}- in pp collisions at \surd s = 1.96 TeV using 360 pb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. A displaced vertex trigger selects long-lived D0 candidates in the {\mu}+ {\mu}-, {\pi}+{\pi}-, and K-{\pi}+ decay modes. We use the Cabibbo-favored D0 \to K-{\pi}+ channel to optimize the selection criteria in an unbiased manner, and the kinematically similar D0 \to{\pi}+ {\pi}- channel for normalization. We set an upper limit on the branching fraction (D0 --> {\mu}+ {\mu}-) < 2.1 E-7 (3.0 E-7) at the 90% (95%) confidence level.
The Deterministic Annealing Filter: A new clustering method for gamma-ray tracking algorithms
2010
A new method of clustering for forward-tracking algorithms has been developed to reconstruct the tracks of gamma-rays in high-resolution detector systems such as AGATA (Advanced GAmma Tracking Array). This technique, called Deterministic Annealing Filter (DAF), comes from statistical physics and is used in high-energy physics. After a description of the DAF method and of the forward-tracking algorithm, the performance of this clustering method is discussed in terms of photopeak efficiency and peak-to-total ratio obtained with GEANT4 simulations for the AGATA geometry. A comparison with the standard so-called "cone clustering method" shows similar performances with a better photopeak efficie…
Total-variation-based methods for gravitational wave denoising
2014
We describe new methods for denoising and detection of gravitational waves embedded in additive Gaussian noise. The methods are based on Total Variation denoising algorithms. These algorithms, which do not need any a priori information about the signals, have been originally developed and fully tested in the context of image processing. To illustrate the capabilities of our methods we apply them to two different types of numerically-simulated gravitational wave signals, namely bursts produced from the core collapse of rotating stars and waveforms from binary black hole mergers. We explore the parameter space of the methods to find the set of values best suited for denoising gravitational wa…
Observation of the rare decayB+→K+π0π0and measurement of the quasi-two-body contributionsB+→K*(892)+π0,B+→f0(980)K+, andB+→χc0K+
2011
We report an analysis of charmless hadronic decays of charged B mesons to the final state K{sup +}{pi}{sup 0}{pi}{sup 0}, using a data sample of (470.9 {+-} 2.8) x 10{sup 6} B{bar B} events collected with the BABAR detector at the {Gamma}(4S) resonance. We observe an excess of signal events, with a significance above 10 standard deviations including systematic uncertainties, and measure the branching fraction and CP asymmetry to be {Beta}(B{sup +} {yields} K{sup +}{pi}{sup 0}{pi}{sup 0}) = (16.2 {+-} 1.2 {+-} 1.5) x 10{sup -6} and A{sub CP}(B{sup +} {yields} K{sup +}{pi}{sup 0}{pi}{sup 0}) = -0.06 {+-} 0.06 {+-} 0.04, where the uncertainties are statistical and systematic, respectively. Add…
Search for the rare decaysB0→Ds(*)+a0(2)−
2006
We have searched for the decays B{sup 0}{yields}D{sub s}{sup +}a{sub 0}{sup -}, B{sup 0}{yields}D{sub s}*{sup +}a{sub 0}{sup -}, B{sup 0}{yields}D{sub s}{sup +}a{sub 2}{sup -} and B{sup 0}{yields}D{sub s}*{sup +}a{sub 2}{sup -} in a sample of about 230x10{sup 6} {upsilon}(4S){yields}BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find no evidence for these decays and set upper limits at 90% C.L. on the branching fractions: B(B{sup 0}{yields}D{sub s}{sup +}a{sub 0}{sup -})<1.9x10{sup -5}, B(B{sup 0}{yields}D{sub s}*{sup +}a{sub 0}{sup -})<3.6x10{sup -5}, B(B{sup 0}{yields}D{sub s}{sup +}a{sub 2}{sup -})<1.9x10{sup -4}, and B(B{sup 0}{yields}D…
Measurement of theB−→D0K*−branching fraction
2006
From a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II B Factory in 1999-2004, they measure the B{sup -} {yields} D{sup 0} K*{sup -}(892) decay branching fraction using events where the K*{sup -} is reconstructed in the K{sub S}{sup 0}{pi}{sup -} mode and the D{sup 0} in the K{sup -}{pi}{sup +}, K{sup -}{pi}{sup +}{pi}{sup 0}, and K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} channels: {Beta}(B{sup -} {yields} D{sup 0}K*{sup -}(892)) = (5.29 {+-} 0.30 (stat) {+-} 0.34 (syst)) x 10{sup -4}.
Measurement of theγγ*→ηandγγ*→η′transition form factors
2011
We study the reactions e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sup (/)} in the single-tag mode and measure the {gamma}{gamma}* {yields} {eta}{sup (/)} transition form factors in the momentum transfer range from 4 to 40 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
Search forB0→K*+K*−
2008
The authors report the results of a search for the decay B{sup 0} {yields} K*{sup +}K*{sup -} with a sample of 454 {+-} 5 million B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the Stanford Linear Accelerator Center. They obtain an upper limit at the 90% confidence level on the branching fraction for {Beta}(B{sup 0} {yields} K*{sup +}K*{sup -}) < 2.0 x 10{sup -6}, assuming the decay is fully longitudinally polarized.